Validity and reliability of the Colorado Adult Joint Assessment Scale in adults with moderate‐severe hemophilia A

Abstract

Background The Colorado Adult Joint Assessment Scale (CAJAS) is designed to assess joint health in adults with hemophilia. The CAJAS comprises nine items (swelling, muscle atrophy, axial deformity, crepitus, range of motion, contracture, instability, strength, gait) and assesses six joints. Objective To assess CAJAS content validity and psychometric properties. Patients/Methods Data were obtained from the Trial to Evaluate the Effect of Secondary Prophylaxis With rFVIII Therapy in Severe Hemophilia A Adult and/or Adolescent Subjects Compared to That of Episodic Treatment (SPINART) study and a separate CAJAS validation study. CAJAS assessments in SPINART were performed by physical therapists (PTs) from the United States, Romania, Bulgaria, and Argentina. In the validation study, content validity was assessed from interviews with six PTs at three US hemophilia centers; cultural equivalence was assessed with seven non‐US PTs from SPINART. Reliability data were collected from 30 subjects at four US centers. Test‐retest reliability was evaluated by having the same PT perform CAJAS examinations at two visits, 7‐10 days apart. Inter‐rater reliability was assessed by comparing CAJAS scores of two different PTs performing separate examinations of the same patient several hours apart at the same visit. Psychometric properties were assessed using SPINART and validation study data. Results The CAJAS demonstrated good content validity. Test‐retest reliability was high (intraclass correlation coefficient, 0.98), as was inter‐rater reliability (intraclass correlation coefficient, 0.88). Internal consistency reliability was strong (α = .90). The CAJAS demonstrated good convergent/divergent validity, known‐groups validity, and ability to detect change. Conclusions The CAJAS is a valid and reliable measure of joint health in adults with moderate‐severe hemophilia and is appropriate for use in clinical practice.

Young adult outcomes of childhood prophylaxis for severe hemophilia A: results of the Joint Outcome Continuation Study

“…Complete psychometric validity has not yet been established for the pediatric Colorado Joint Assessment Scale; however, the related Colorado Adult Joint Assessment Score (CAJAS) has been fully validated. 34 The CPJAS has been shown to have good interrater reliability, and normal values have been established in agematched healthy controls. 20 The CPJAS was chosen because it preserved all of the elements of the original JOS score.…”

Effect of late prophylaxis in hemophilia on joint status: a randomized trial

“…The CAJAS, which was designed and validated to measure the joint health of six index joints in adults (derived from the WFH scale [i.e the Gilbert score] ) was used. The CAJAS provides an overall score derived from nine items for knees and ankles, and seven items for elbows.…”

Patient‐relevant health outcomes for hemophilia care: Development of an international standard outcomes set

“…Selection was primarily based on the fit of the instrument's contents with the health outcome to properly measure the outcome. Then, selection was based on the (i) instrument's psychometric quality (extracted from systematic reviews and recent literature) 15,20,[24][25][26][27][28][29][30][31] ; (ii) number of available validated translations; and (iii) instrument's availability and accessibility.…”